You can also try fiddling with the environmental settings in TMPGEnc, AVI reader to highest and make sure you have the codecs to read the file, as otherwise you will not be able to open it with either.

The best results come from uncompressing the audio so thats what i always do! I used to tell people to raise the DirectShow File Reader priority until it was at the top of the list but about 40% still came back and said something like, there still is no audio or the audio is out of sync or the audio sounds really bad etc etc... wheras uncompressing has had a 100% success rate so far, im still waiting to hear either of the above remaining problems